The present invention relates to a magnetic recording head having a function for inducing magnetization reversal by applying a high-frequency magnetic field to a magnetic recording medium, and to a magnetic recording and reading device.
In order to achieve higher recording density for a magnetic head mounted in a hard disk device, it is necessary to narrow the write track pitch and bits. The surface area of the main pole at the air bearing surface decreases considerably as the recording density increases. The recording field becomes smaller as the main pole becomes narrower in this way in a conventional magnetic head, and above a certain recording density, it no longer becomes possible to achieve the recording field required for writing. To address this issue, a high-frequency magnetic field-assisted recording method (MAMR: microwave-assisted magnetic recording) has been proposed, in which a microwave oscillator (spin torque oscillator) is formed on or near the main pole, and a high-frequency magnetic field is applied to the recording medium in order to reduce the coercive force of the medium, and in this state, a recording field is applied to the medium in order to record data. In addition, a method has also been proposed in which the recording portion of the main pole is inclined with respect to the substrate surface, a microwave oscillator is disposed on the inclined surface, and the head field intensity is effectively increased.
When a microwave oscillator is formed on the main pole, a very accurate pattern needs to be formed for the shape of the oscillator. With conventional manufacturing methods, if the recording portion of the main pole is inclined with respect to the substrate surface, unevenness is produced in the wafer surface, and the inclined part on the trailing side of the main pole becomes concave with respect to the wafer surface. Thus, it becomes difficult to form a highly accurate pattern when the microwave oscillator pattern is formed. Particularly, when chemical mechanical polishing (CMP) is used in order to form the microwave oscillator, it is difficult to process the concave parts on the uneven wafer surface. Consequently, the microwave oscillator is preferably formed on a flat part.